Merge tag 'landlock-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux

Pull landlock updates from Mickaël Salaün:
 "This brings ioctl control to Landlock, contributed by Günther Noack.
  This also adds him as a Landlock reviewer, and fixes an issue in the
  sample"

* tag 'landlock-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
  MAINTAINERS: Add Günther Noack as Landlock reviewer
  fs/ioctl: Add a comment to keep the logic in sync with LSM policies
  MAINTAINERS: Notify Landlock maintainers about changes to fs/ioctl.c
  landlock: Document IOCTL support
  samples/landlock: Add support for LANDLOCK_ACCESS_FS_IOCTL_DEV
  selftests/landlock: Exhaustive test for the IOCTL allow-list
  selftests/landlock: Check IOCTL restrictions for named UNIX domain sockets
  selftests/landlock: Test IOCTLs on named pipes
  selftests/landlock: Test ioctl(2) and ftruncate(2) with open(O_PATH)
  selftests/landlock: Test IOCTL with memfds
  selftests/landlock: Test IOCTL support
  landlock: Add IOCTL access right for character and block devices
  samples/landlock: Fix incorrect free in populate_ruleset_net

1 files changed, 30 insertions, 8 deletions

diff --git a/include/uapi/linux/landlock.h b/include/uapi/linux/landlock.h
index 25c8d7677539..68625e728f43 100644
--- a/include/uapi/linux/landlock.h
+++ b/include/uapi/linux/landlock.h
@@ -128,7 +128,7 @@ struct landlock_net_port_attr {
  * files and directories.  Files or directories opened before the sandboxing
  * are not subject to these restrictions.
  *
- * A file can only receive these access rights:
+ * The following access rights apply only to files:
  *
  * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a file.
  * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access. Note that
@@ -138,12 +138,13 @@ struct landlock_net_port_attr {
  * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a file with read access.
  * - %LANDLOCK_ACCESS_FS_TRUNCATE: Truncate a file with :manpage:`truncate(2)`,
  *   :manpage:`ftruncate(2)`, :manpage:`creat(2)`, or :manpage:`open(2)` with
- *   ``O_TRUNC``. Whether an opened file can be truncated with
- *   :manpage:`ftruncate(2)` is determined during :manpage:`open(2)`, in the
- *   same way as read and write permissions are checked during
- *   :manpage:`open(2)` using %LANDLOCK_ACCESS_FS_READ_FILE and
- *   %LANDLOCK_ACCESS_FS_WRITE_FILE. This access right is available since the
- *   third version of the Landlock ABI.
+ *   ``O_TRUNC``.  This access right is available since the third version of the
+ *   Landlock ABI.
+ *
+ * Whether an opened file can be truncated with :manpage:`ftruncate(2)` or used
+ * with `ioctl(2)` is determined during :manpage:`open(2)`, in the same way as
+ * read and write permissions are checked during :manpage:`open(2)` using
+ * %LANDLOCK_ACCESS_FS_READ_FILE and %LANDLOCK_ACCESS_FS_WRITE_FILE.
  *
  * A directory can receive access rights related to files or directories.  The
  * following access right is applied to the directory itself, and the
@@ -198,13 +199,33 @@ struct landlock_net_port_attr {
  *   If multiple requirements are not met, the ``EACCES`` error code takes
  *   precedence over ``EXDEV``.
  *
+ * The following access right applies both to files and directories:
+ *
+ * - %LANDLOCK_ACCESS_FS_IOCTL_DEV: Invoke :manpage:`ioctl(2)` commands on an opened
+ *   character or block device.
+ *
+ *   This access right applies to all `ioctl(2)` commands implemented by device
+ *   drivers.  However, the following common IOCTL commands continue to be
+ *   invokable independent of the %LANDLOCK_ACCESS_FS_IOCTL_DEV right:
+ *
+ *   * IOCTL commands targeting file descriptors (``FIOCLEX``, ``FIONCLEX``),
+ *   * IOCTL commands targeting file descriptions (``FIONBIO``, ``FIOASYNC``),
+ *   * IOCTL commands targeting file systems (``FIFREEZE``, ``FITHAW``,
+ *     ``FIGETBSZ``, ``FS_IOC_GETFSUUID``, ``FS_IOC_GETFSSYSFSPATH``)
+ *   * Some IOCTL commands which do not make sense when used with devices, but
+ *     whose implementations are safe and return the right error codes
+ *     (``FS_IOC_FIEMAP``, ``FICLONE``, ``FICLONERANGE``, ``FIDEDUPERANGE``)
+ *
+ *   This access right is available since the fifth version of the Landlock
+ *   ABI.
+ *
  * .. warning::
  *
  *   It is currently not possible to restrict some file-related actions
  *   accessible through these syscall families: :manpage:`chdir(2)`,
  *   :manpage:`stat(2)`, :manpage:`flock(2)`, :manpage:`chmod(2)`,
  *   :manpage:`chown(2)`, :manpage:`setxattr(2)`, :manpage:`utime(2)`,
- *   :manpage:`ioctl(2)`, :manpage:`fcntl(2)`, :manpage:`access(2)`.
+ *   :manpage:`fcntl(2)`, :manpage:`access(2)`.
  *   Future Landlock evolutions will enable to restrict them.
  */
 /* clang-format off */
@@ -223,6 +244,7 @@ struct landlock_net_port_attr {
 #define LANDLOCK_ACCESS_FS_MAKE_SYM			(1ULL << 12)
 #define LANDLOCK_ACCESS_FS_REFER			(1ULL << 13)
 #define LANDLOCK_ACCESS_FS_TRUNCATE			(1ULL << 14)
+#define LANDLOCK_ACCESS_FS_IOCTL_DEV			(1ULL << 15)
 /* clang-format on */
 
 /**